Plate-shaped cover material

ABSTRACT

Plate-shaped cover material comprising an elastomeric layer and a plastically deformable metal mesh or metal plate, the elastomeric layer consisting of a glue or joint sealant cured to an elastomer and having strong adhesion to the metal mesh or the metal plate.

TECHNICAL FIELD

[0001] The invention relates to a plate-shaped cover material comprisingan elastomeric layer and a plastically deformable metal mesh or metalplate. Such cover materials are particularly used for flashing rooflead-ins, such as chimneys, skylights, air ducts, attics and the like.The cover material is further suitable for preformed, plasticallydeformable flashing sections and the like building members.

BACKGROUND ART

[0002] DE 3642063 discloses a cover material according to the preambleof claim 1, and wherein the elastomeric layer is formed of a non-tackypolyisobutylene substrate (PIB). The cover material is provided with anadhesive layer for being sealed to a base, eg a roof, in connection witha roof lead-in. Wax is added so as to protect the polyisobutylenesubstrate against ozone. At high temperatures, eg on a hot summer's day,the wax may escape from the polyisobutylene substrate and thus ruin thebonding to the base, whereby the material may slide. Furthermore, thesurface is not suitable for being painted over.

[0003] DE 3310989 disclosed a plastically deformable cover materialcomprising an elastomeric layer and a plastically deformable metal mesh.The elastomer material is made from a rubber material, preferablyvulcanizable EPDM rubber (ethylene-propylene rubber). Variousreinforcing fillers and vulcanizing accelerators are often added to thispolymer material to obtain sufficiently strong mechanical properties.These additives hampers the adhesiveness of the material such thatlong-term adhesion is difficult to obtain.

[0004] DE 2225358 discloses a plastically deformable cover materialcomprising an elastomeric layer and a plastically deformable metal mesh,the elastomeric layer comprising a non-adhesive bitumen-rubber compoundon one side and a self-adhesive bitumen-rubber layer on the other side.A draw-back of this cover material is that suitable bitumen compositionshave a softening point of between 70° C. and 175° C. resulting inlimited low-temperature formability thereof. Furthermore bitumen-basedmaterials are not suitable for bonding by means of conventional gluesand joint sealants.

[0005] EP 0 923 363 discloses the use of inter alia polyurethane incover materials of the above type.

[0006] U.S. Pat. No. 5,414,964 discloses a cover material in whichEPDM-rubber is used as elastomer.

BRIEF DESCRIPTIONS OF THE INVENTION

[0007] The object of the invention is to provide a new and improvedcover material of the above type, said material being particularlyimproved as regards deformability, density, adhesiveness and strength.

[0008] According to the invention the object is obtained in that theelastomeric layer is formed of a glue or an joint sealant to whichadhesion promoters have been added, said glue or joint sealant beingcured to an elastomer and having strong adhesion to the metal mesh ormetal plate in its cured stated. Glues, sealing compounds or jointsealants are usually used for bonding materials and/or for fillingjoints in structures in order to absorb dimensional changes due to forinstance temperature variations or contractions of volume. The adhesionof these sealants to the materials with which they bond is typicallyequal to the cohesive forces of the sealant. If the cohesive forces ofthe glue, joint sealant or adhesive equal the cohesive forces of thebonded materials, a new break due to excess load typically takes placeoutside of the glue joint. By using such an adhesive for manufacturingthe elastomeric layer of the plate-shaped cover material a very strongmaterial is obtained. Even though the cover material is heavily deformedduring and after mounting, the material retains its density as a resultof the strong adherence of the elastomer to the metal plate or the metalmesh. Often it is unnecessary to pre-treat the metal mesh or the metalplate with a primer to obtain strong and effective adhesion. Anotheradvantage is that the same type of glue or joint sealant as the one fromwhich the elastomer is made may be used for adhering the cover materialto the base. A particularly strong and secure adhesion is thus ensured.

[0009] Such glue and joint sealants may typically be based on a MSpolymer, polyurethane or silicone.

[0010] MS polymers are materials primarily used for glueing and jointsealing and not as basis material in a moulding material. The materialis made by a silane modification of a polymer resulting in a polymercomposition able to adhere to most surface types and curing to anelastomer when subjected to moisture.

[0011] U.S. Pat. No. 5,714,257 discloses the use of MS polymers in theproduction of extruded, non-woven fibre webs for various applicationsand mentions suitable silanes and polymers for this purpose.

[0012] Sealing compounds, joint sealants and the like based on MSpolymers are sold under brand names like for instance Casco buildingjoint sealant S40 containing 1-5% of vinyltrimethoxysilane, 10-30% of MSpolymer and 30-60% of calcium carbonate.

[0013] The MS polymer may for instance be polyoxypropylene. Previously,10-30% of diisodecyl phthalate were added as plasticiser, but today thiscompound has been replaced by plasticising compounds without compulsorymarking in Denmark.

[0014] Corresponding products from Simson Industry are sold under thebrand name ISR 70-xx and contain 2.5% of alkoxysilane, 30-60% ofpolyether polymer (MS polymer) and 30-60% of calcium carbonate.

[0015] Henkel also sells MS polymer-based sealants and glue under suchbrands as Terostat MS 930. Dana Lim sells inter alia the brand MS 520.

[0016] According to the invention the glue or joint sealant may be basedon a MS polymer. This material has an excellent adhesiveness and aparticularly strong adhesion to the metal mesh or the metal plate may beobtained by means of a curing process. It is also easy to seal the covermaterial to various types of bases during mounting thereof by means of aMS adhesive or other joint sealants, common joint sealants adheringstrongly to cured MS polymers, said MS polymers also beingpaint-compatible. Moreover MS polymers are highly elastic over a largetemperature span, thus allowing deformation of the cover materialwithout causing cracking and consequent leaks. Finally MS polymers arework-environmentally sound materials. Casco MS 20 is typically used forindoor joints in buildings and has the OAR (occupational airrequirement) code 001, confer the Danish Working Environment Service'sAdministrative Orders about establishment of and work with code numbers,Orders No 301 and 302 of May 13, 1993.

[0017] According to the invention the elastomeric layer may comprise0.01-10% by weight of silane, 10-60% by weight of MS polymer and 30-60%by weight of calcium carbonate. This material has proved particularlysuitable.

[0018] The glue or joint sealant may according to the invention be basedon a silane-modified polyurethane.

[0019] According to the invention the glue or joint sealant may be basedon a hybrid non-isocyanate polyurethane (HNIPU). This material isadvantageous in that the use of isocyanate is avoided, said substancebeing environmentally unsound.

[0020] The glue or joint sealant may finally be based on silicone.Silicone is advantageous in that it can tolerate very high temperatures,viz, to a high of 300° C.

[0021] According to the invention the cover material may comprise areinforcement layer of a permeable material pre-treated for sealing, eg.a non-woven felt layer of polypropylene. An increased strength is thusobtained, the reinforcement layer limiting the plastic deformation andthus minimizes the risk of cracking and consequent leaks. Due topermeability of the reinforcement layer, the cohesive force of theelastomeric layer is not greatly reduced.

[0022] According to the invention the reinforcement layer may bearranged at the lower side of the cover material. As a result themoulding of the cover material is facilitated in that the finished covermaterial may be removed from the mould due to a slight porosity on thelower side resulting from the reinforcement layer. This porosity hassurprisingly proved to provide an increased adhesion to the base, theadhesive penetrating into the pores.

[0023] According to an embodiment the metal mesh may be formed of anexpanded metal grid, whereby a high plastic deformability is ensured.

[0024] In order to increase the plastic deformability the expanded metalgrid is made from aluminium.

[0025] The expanded metal grid may be recrystallized by a suitable heattreatment so as to reduce the deformation tensions arising at themanufacture of the expanded metal grid, whereby the expanded metal gridis more readily deformed.

[0026] According to an embodiment in order to enhance the rigidity, theplate-shaped cover material may in places be provided with additionalreinforcement layers, metal meshes or metal plates optionally beingperforated. An increased rigidity in desired places and an increaseddeformability in desired places are thus obtained.

[0027] According to the invention the upper face of the cover materialmay be coated with an UV-impenetrable material, eg in form of a coatingmaterial comprising slate so as to obtain an excellent and effectiveultraviolet light protection of the cover material as well as anaesthetic appearance.

[0028] According to the invention the cover material may be shaped as astrip being provided with a self-adhesive tape on one side along onerim. This embodiment is particularly advantageous in that theself-adhesive tape may ensure sealing of the cover material to a baseduring mounting prior to the final bonding by means of a suitableadhesive. This is particularly advantageous when flashing for instance around or square lead-in, eg a chimney led through a slanting roof, theself-adhesive tape retaining the strip, while this is being deformed toclose abutment with the chimney and the roof, respectively. By means ofthis strip extremely strong transitions between roof lead-ins and roofsor cover materials are obtained, said transitions relieving the load onthe cover material and rendering the use of cover strips, eg of metal,superfluous. The strip may optionally be bent about 90° to form aflashing section.

[0029] An adhesion promoter based on silanes or amines may be added tothe glue or joint sealant according to the invention.

[0030] The invention also relates to a method for the manufacture of acover material according to one of the preceding claims and in which apermeable reinforcement layer of for instance non-woven polypropylenefelt optionally is placed in the bottom of a mould, the glue or jointsealant is spread in the mould by means of a filling process, injectionprocess or by another process, whereafter the deformable metal mesh ispressed down into the glue or joint sealant and any optionalreinforcement layers are arranged, and in which ground slate optionallyis scattered on top of the glue or joint sealant, before the lattercures, whereafter the cover material is removed from the mould.

[0031] Heat or moisture may be added so as to accelerate the curingprocess.

[0032] A vapour-permeable material with low surface tension mayoptionally be placed in the bottom of the mould. With a view to anaccelerated curing process, vapour may be added to the glue or jointsealant. Similarly the plate material may be removed from the mould bymeans of a permeable material layer, before complete curing of the glueor joint sealant for better utilization of the mould. PE (polyethylene)and PP (polypropylene) are both suitable for this purpose due to the lowsurface tension thereof, whereby the permeable layer may be removedeasily from the fully cured glue or joint sealant. A particular suitablematerial has proved to be TYVEK® marketed by DuPont. The TYVEK® layermay remain on the finished product, as it possesses excellent anti-dripproperties. If the TYVEK® layer (or another layer with similarproperties) remains in an area sealing the gap between the roof and thelead-in, the draw-back of condensed water dripping into the gap isreduced.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The invention is described in greater detail below with referenceto the accompanying drawing, in which

[0034]FIG. 1 is a diagrammatic sectional view through a first embodimentof the cover material according to the invention,

[0035]FIG. 2 is a diagrammatic sectional view through a secondembodiment of the cover material according to the invention,

[0036]FIG. 3 is a diagrammatic sectional view through a third embodimentof the cover material according to the invention,

[0037]FIG. 4 is a sectional view through a roof lead-in, the covermaterial according to the invention being used as flashing material,

[0038]FIG. 5 is a sectional view through a roof lead-in, the covermaterial according to the invention being used as flashing material inanother manner,

[0039]FIG. 6 is a sectional view through a roof lead-in, the covermaterial according to the invention being used as flashing material in athird manner, and

[0040]FIG. 7 is a diagrammatic sectional view through a fourthembodiment of the cover material according to the invention.

BEST MODES FOR CARRYING OUT THE INVENTION

[0041] The embodiment shown in FIG. 1 simply consists of an expandedmetal grid 2 of aluminium and an elastomeric layer 1 comprising MSpolymer. By means of a suitable heat treatment at about 300° C. theexpanded metal grid 2 has been recrystallized to obtain a high plasticdeformability. The MS polymer of the elastomer may be any MS polymerpossessing the desired properties. Casco Bygfuge S20 containing 1-5% ofvinyltrimethoxysilane, 10-30% of polyoxypropylene (MS polymer) and30-60% of calcium carbonate is used in the embodiment shown. In itscured state this compound has a Shore A hardness of 20-30. The aluminiumexpanded metal grid has a mesh size of 10×5 mm, a rib width of 1.5 mmand a rib thickness of 0.9 mm. The thickness of the cover material perse, ie of the elastomeric layer, is about 3 mm.

[0042] The embodiment of the cover material according to the inventionshown in FIG. 2 is provided with a UV-protecting layer 3 of groundslate. The slate has paint compatibility. The upper face 3 mayoptionally be provided with a layer of sand, fine shingles or copperfoil. The lower face is provided with a reinforcement layer 4 in form ofa non-woven polypropylene felt sold under the brand name “Plantexfixrulle” (trade mark registered by DuPont) with the type designation3207. This material is UV-stabilised and sold as a so-called geotextile,which inter alia is used to distribute loads under gravel and tiles. Thereinforcement layer has a thickness of about 0.3 mm and increases thestrength of the cover material and prevents cracking and the like in theelastomeric layer caused by excessive plastic deformation. In order toenhance the adhesion of the reinforcement layer to the MS polymer, thesurface thereof is corona-treated prior to the embedment process.However it should be noted that the cover material may be formed aroundvery sharp corners in several directions without being damaged. Thepores of the reinforcement layer is filled up by the elastomer duringmoulding of the cover material, whereby the surface of the elastomerensures a subsequent strong adhesion to a base. The lower face is,however, semi-porous, which has proved to provide a particular strongadhesion to a base when MS polymer is also used for sealing.

[0043] The embodiment shown in FIG. 3 differs from the one shown in FIG.1 in that a self-adhesive tape 5 is embedded in the lower face by meansof which the cover material may be sealed during the mounting per se,the mounting process thus being facilitated. The tape used in this caseis a so-called VHB-tape based on a viscoelastic acrylic adhesive. Ametal foil strip 6 is provided between the tape and the elastomer toprevent mixing of the non-cured MS polymer and the acrylic adhesiveduring moulding of the cover material.

[0044]FIG. 7 illustrates an embodiment, in which a metal plate 2 is usedinstead of a metal mesh. Areas of the lower face thereof are providedwith an additional metal plate 15. The additional metal plate 15 istypically arranged adjacent the edge of a strip-shaped cover material,which is to abut a roof lead-in, whereby increased rigidity is obtainedin this area. The additional metal plate 15 may be made fromrecrystallised aluminium. As can be seen in FIG. 7, the VHB-tape isfixed to the lower face of the additional metal plate 15.

[0045] Common dual adhesives, typically with acrylic base, are alsoapplicable in that they only have to keep the assembly in place, untilthe MS polymer used for the mounting has cured. The shown additionalplate 15 is provided with perforations 16 to weaken the rigidityadjacent the area, which is not provided with an additional metal plate15. As a result “softer” transition is obtained. The additional plate 15may otherwise be provided with perforations 16 to provide the desiredrigidity.

[0046] The metal plate 2 may also be provided with perforations toprovide a desired rigidity. The size or closeness of these perforationsmay vary depending on the position on the plate so as to provide varyingrigidity depending on the position. It is thus possible to provide ahigh degree of rigidity in the area close to a roof lead-in and a highdegree of deformability in the area distanced therefrom.

[0047] In FIG. 7 the thickness of both the metal plate 6 and theadditional metal plate 15 is about 0.5 mm.

[0048] In FIG. 7 one of the side rims are folded down 180° to increasethe rigidity so as to minimise the risk of the wind lifting the covermaterial and/or causing it to vibrate resulting in noise and possibledestruction of the flashing.

[0049] The MS polymer has proved particularly suitable for this purposedue to its strong adhesion to the reinforcement layer 4, the expandedmetal grid or the metal plate 2 and the ground slate 3. A particularlystrong adhesion is further obtained when the same material is used asadhesive/joint sealant for sealing the cover material to the base. Thisis most likely due to a “recasting” of the lower face of the covermaterial taking place when this is comes into contact with a non-curedMS polymer.

[0050]FIGS. 4, 5 and 6 illustrate how the cover material in variousembodiments maybe used for flashing a roof lead-in in form of acylindrical metal member 13 through a slanting roof 14. The covermaterial shown in FIGS. 4-6 comprises an expanded metal grid as shown inFIGS. 1-3, the latter, however, being omitted for reasons of clarity.FIG. 4 illustrates a simple embodiment, in which the cover material 10,which may be of the embodiment shown in FIG. 2, is folded and sealed tothe metal cylinder 13 by means of a MS polymer joint sealant 12.Preferably a MS polymer is also used for adhering the lower face of thecover material 10 to the roof 14. As can be seen, ground slate has beenscattered on top of the joint sealant immediately subsequent to theapplication thereof.

[0051]FIG. 5 illustrates a mounting, in which the cover material 10 isfolded along the metal cylinder 13 as seen in FIG. 4, but where anadditional and particularly strong sealing has been made by means of acover material strip 11 with embedded tape 5 as seen in FIG. 3. Thecover material may for instance be provided with expanded aluminium gridlayers 2 and a felt layer arranged therebetween. During mounting thestrip 11 is sealed to the metal cylinder by means of the tape 5 andretained in this position, while being made to abut the cover material10 and sealed thereto by means of the MS polymer joint sealant 12. FIG.6 illustrates a mounting corresponding to that shown in FIG. 5, exceptthat the strips 11 are sealed to the lower face of the cover material 11and that the cover material 11 is sealed to the metal cylinder 13 bymeans of a MS polymer joint sealant 12. In all cases ground slate may becut off or ground off the portion of the surface of the plate material10 to be sealed to the lead-in (FIG. 4) or the strip 11 (FIG. 5). A MSpolymer is typically applied to surfaces to be bonded, outflowing pasteand any additionally provided MS polymer paste being smoothed out to aslanting smooth transition as shown at all the transitions and trims.

[0052] In FIGS. 4, 5 and 6 the strip 11 is arranged about a circularlead-in 13. Due to its flexibility the strip 11 may also readily bemounted integrally about a square lead-in. Despite the bending at 90°the strip 11 retains an angular shape as shown in FIGS. 4, 5 and 6.

[0053] Since the cover material 10 or the cover material strip 11adheres easily and thus enables a particularly strong adhesion to manydifferent surfaces, so-called splats can often be omitted. In connectionwith less sturdy surfaces, where adhesion is insufficient, the strip 11may be used as a ductile splat being mechanically secured by means ofscrews, rivets, nails or by being grouted in between two rows of bricks.For bedding purposes the strip may advantageously be provided with slateon both sides to obtain a strong bond to the mortar.

[0054] The MS polymer forming part of the moulding compound for theelastomeric layer, may have many different compositions. The polymer maybe a polyolefin, eg a styrenic block copolymer, polyester, polyester,polyamide, polyurethane, ethylene vinyl acetate and the like compounds.The silanes for modifying the said polymers may be amino silanes, epoxysilanes, ureido silanes, vinyl silanes or the like. In addition to theMS polymer calcium carbonate may be added to the moulding compound asfiller.

[0055] The invention is not restricted to the above embodiments. Themetal mesh may for instance be a mesh or a grid of for instance steel orzinc. Especially zinc alloys are advantageous in that they can bemanufactured cost-effectively and are easily deformed.

[0056] As the top layer for UV protection—and for obtaining an aestheticappearance—sand or paint may be used in addition to or in replacement ofground slate.

[0057] As noted above an optionally perforated metal plate ofrecrystallized aluminium or zinc may be used instead of a metal mesh.Such an embodiment is typically suitable for applications with lowerdeformability requirements.

[0058] Irrespective of a metal mesh or a metal plate is used as theembedded part, this part may be made from conventional aluminium whichis easily deformed. Conventional aluminium corrodes very easily incertain environments, but in this case it is encapsulated by a MSpolymer and thus corrosion-proof.

[0059] The embodiment shown in FIGS. 1-3 is more rigid than theconventionally used 1 mm lead plate, as about twice the force isrequired for bending it. In return the cover material is considerablystronger than a lead plate after mounting due to strain hardening. Inother respects the cover material according to the invention has many ofthe advantages which have made lead plates popular.

[0060] In the embodiment shown a MS polymer is used for the elastomer.According to the invention the glue or joint sealant used may also bebased on polyurethane or silicone. Especially so-called hybridnon-isocyanate polyurethane/HNIPU is advantageous, the health andenvironmental risks associated with isocyanate during the manufactureand use of conventional polyurethane (PUR) being avoided.Silane-modified polyurethane is also suitable for this purpose due toits particularly strong sealing properties, ie. adhesion.

[0061] Joint sealants based on the various described materials typicallyhave the following elongations at break: MS polymer 300-700%, PUR200-600% and silicone 100-300%.

[0062] The plate-shaped cover material according to the invention istypically produced in webs having a width of up to 1-2 metres. Thesewebs may then be wound up into coils. The cover material may be made bymoulding in moulds or by extrusion.

1. A plate-shaped cover material comprising an elastomeric layer (1) anda plastically deformable metal mesh (2) or a metal plate, characterisedin that the elastomeric layer is formed of a glue or an joint sealantcured to an elastomer and having strong adhesion to the metal mesh ormetal plate.
 2. A plate-shaped cover material according to claim 1,characterised in that the glue or joint sealant is based on a MSpolymer, polyurethane or silicone.
 3. A plate-shaped cover materialaccording to claim 2, characterised in that the glue or joint sealant isbased on a MS polymer and comprises 0.01-10% by weight of silane, 10-60%by weight of MS polymer and 30-60% by weight of calcium carbonate.
 4. Aplate-shaped cover material according to claim 2, characterised in thatthe glue or joint sealant is based on silane-modified polyurethane.
 5. Aplate-shaped cover material according to claim 2, characterised in thatthe glue or joint sealant is based on hybrid non-isocyanate polyurethane(HNIPU).
 6. A plate-shaped cover material according to claim 2,characterised in that the glue or joint sealant is based on silicone. 7.A-plate-shaped cover material according to one of the preceding claims,characterised in that it comprises one or more reinforcement layers (4)of a permeable material.
 8. A plate-shaped cover material according toclaim 7, characterised in that the reinforcement layer is a non-wovenfelt layer (4) of polypropylene.
 9. A plate-shaped cover materialaccording to claim 7 or 8, characterised in that the reinforcement layer(4) is arranged at the lower face of the cover material.
 10. Aplate-shaped cover material according to one of the preceding claims,characterised in that the metal mesh is an expanded metal grid (2). 11.A plate-shaped cover material according to claim 10, characterised inthat the expanded metal grid (2) or the metal plate is made fromaluminium and optionally recrystallized by heat treatment.
 12. Aplate-shaped cover material according to one of the preceding claims,characterised in that areas of thereof are provided with an additionalreinforcement layer (4), metal mesh or metal plate (4) to increase therigidity.
 13. A plate-shaped cover material according to one of thepreceding claims, characterised in that the surface is coated with anupper layer (3) of an UV-impenetrable material, in particular groundslate.
 14. A plate-shaped cover material according to one of thepreceding claims, characterised in that it is shaped as a strip beingprovided with a self-adhesive tape (5) along one rim of one side.
 15. Aplate-shaped cover material according to one of the preceding claims,characterised in that an adhesion promoter, eg based on silanes oramines, is added to the glue or joint sealant.
 16. A method for themanufacture of a plate-shaped cover material according to one of thepreceding claims and in which a permeable reinforcement layer, eg. of anon-woven polypropylene felt, optionally is placed in the bottom of amould, whereafter the deformable metal mesh is pressed down into theglue or joint sealant and any optional reinforcement layers arearranged, and in which ground slate optionally is scattered on top ofthe glue or joint sealant, before the latter cures, whereafter the covermaterial is removed from the mould.